THANG MAy vA MAy NANG
§3.1. KHAI NI~M CHUNG
Thang may (may nAng) 18. thi~t hi vl\ln tAi dung d~ cha hang va ngubi thea phl1dng
thing dung. Nhting IOlili thang may hi~n
d~i cd ket cAU cd kht phuc t!ilP, M truy~n d/,'lng, M th6ng kh6ng chI! phuc t!;lP - nh~m
'. nang caa na.ng sullt, vl\ln hanh tin cl\ly, an toano Tilt ca cae thi~t hi di{}n dUQc M.p ~t trong bu6ng thang va bu6ng may. Bu6ng may thubng b6 trl " bing tr~n cung cua giifng thang may. Kift ellu, sa do b6 trl thiift bi cua thang may gWi thi~u tr~n binh 3-1.
H6 gil!ng cua thang may 11 lit khoAng
khOng gian tu m(lt bAng sAn bing 1 cho
den day gi«ng. N«u h6 ¢ng cO dQ sAu hdn
2m thl phAi lam thAm cua ra vao. D~ nAng - h~ hu6ng ~hang, ngubi ta dung d/)ng Cd
6. DOng Cd 6 dUQc n6i tn,iC ti~p viJi CO diu
nAng ho~ qua hQp giAm tde. N«u n6i tn,iC
ti«p, hu6ng thang dUQc tree l~n pUli qutln c~p. N~u n6i gi~n ti«p thl giua pUli qutln cap vA dOng co cO lAp hQp giAm t6c 5 vl'li
ti 86 tnly~n i == 18 + 120.
Khung cUa bu6ng thang 3 dl1Qc tree l~n puB qutln c~p bAng cap kim le~i 4 (thl1ang dung 1 d~n 4 sQi cap).
Bu6ng thang luOn luOn dUQc giu theo phuong thAng dang nhb cO gia tree 7 va nhung con trl1Qt dAn hl1l'1ng (con truc;Jt la lo~i puli truc;Jt cd bQc cao Bll b~n ngeai). Bu6ng thang vA d6i trQng di chuy~n dQc
28
-144-- 11
'.
thea ehieu eaa eua thanh gi~ng thea cae thanh dAn httong 9.
Bu6ng thang co trang b~ bl) phanh hia hi~m (phanh du). Phanh baa hi~m giu bu6ng thang t~i eM khi dut cap, mfit di~n va khi t6c d¢ di chuygn Vligt qua (20+40)% t6e
dl) dtnh mac.
Phanh haa hil!m tbttbng dugc eM' t.f.ta thea 3 kil!u : phanh baa hiem kieu n@m, phanh baa hiem kigu l~ch tdm vA phanh baa hiem kigu kim.
Trang cae lal;l.i phanh tr€m, phanh baa hi~m kieu kim dugc su dl,lng r¢ng "tAi helD, no dam baa eha bu6ng thang dung @m han. K~t eliu clla phanh baa hiem kieu kim dugc hil!u di~n tren Mnh 3-2.
Phanh baa higm thuang dUQe lAp phia duai bu6ng thang, g<;>ng kim 2 trugt thea thanh dAn huang 1 khi t6c dQ ella. budng thang blnh thu:ang. N~m giua hai canh tay don clla kim co n@m 5 gAn voi M truy~n dOng banh vlt - tr1,lc vlt 4. H~ truyt!n d¢ng tr\lc vit co hai la~i ren : ren phai va ren trai.
Cung voi k~t eliu ella phanh bAa hiem, buang thang cO trang bt tMm ca cau h~n che t6e de;; kil!u ly tAm. Khi bu6ng thang di chuygn se lam eha ea el1u h(ln ch~ t6c dl) kieu ly tam quay. Khi t6e de;; di ehuyen clla bu6ng thang tang, co eliu dai truy~n 3 se lam cha tang 4 quay va klm 5 se ep ch~t bu6ng thang vaa thanh dAn huang va h~n che' tde d¢ ella bu6ng thang.